Variable-delivery oil pump



Feb. 5, 1929. 1,701,485

E. c. ZISTERER VARIABLE DELIVERY OIL FUIR Filed Jan. '7, 1927 lZUIZiOT'I 221g Z22 LZzbterer,

Patented Feb. 5, 1929.

UNITED. STATES PATENT OFFICE.

EMIL C. ZISTEREB. OF IBERWYN, ILLINOIS,-ASSIGNOR OI ONE-THIRD TO HENRY G. BUCHHOLZ, OF LA; GRANGE, ILLINOIS, AND ONE-THIRD TO GEORGE J. ZISTERER,

OF GICERO, ILLINOIS.

VARIABLE-DELIVERY on. PUMP.

Application filed January 7, 1927. Serial No. 159,678.

This invention relates to variable delivery oil pumps, and its principal object is to pro vide automatically operating means for varying the amount of oil delivered by the pump.

'This invention has particular reference to electric motor driven oil pumpssuchas are used in connection with oil burners for heating systems or other places Where oil burner systems are employed. Such systems usually employ a pressure switch for opening and closing the electric circuit to the pump motor and frequently employ a thermostat (located in a place heated by the plant) for controll ng the operation of the motor. In many 1nstances, however, the pressure in the boiler reaches a maximum and the pressure switch is thereupon operated to break the circuit and stop the pump motor, before the heat in the rooms, heated by the steam heating system, has reached a temperature at which the thermostat will operate, with the result that sometimes the thermostat operates to close the switch and start the motor immediatelyafter it has been stopped and while the fire bricks in the combustionchamber of the boiler are intensely hot thereby causing explosions unless the ignition means operates to ignite the oil, thereby doing great damage to the plant as well as to the building in which the plant is contained.

In accordance with the present invention the oil pump operates to deliver a maximum quantity of oil when there is no pressure or when the pressure is low in the boiler and it automatically operates to reduce the supply of oil as the pressure in the boiler increases, and in case the pressure in the boiler thereafter decreases, the pump operates to pump oil faster until the pressure again increases whereupon the supply of oil gradually decreases so that when the pressure is suflicient to operate the pressure switch and'thereby stop the motor, only a relative small quantity of oil is being delivered at the time the pump is stopped. If the thermostat in such case should act to close the switch again, and in case the ignition means fail to operate, only a small quantity of oil will be delivered at such time thereby lessening, if not entirely eliminating, any danger of explosion in the furnace. .The invention consists therefore 'in' a variable delivery oil pump having automatic means under the control of a steam pressure operated device for regulating the quantity of oil delivered, whereby the volume of oil decreases as the pressure rises in the boiler. The invention further consists in the several novel features hereinafter fully set forth and claimed. I

. The invention is clearly illustrated in the drawing accompanying this specification, in which:

Fig. 1 is a diagrammatic view of a variable delivery oil pump and showing its connection with the steam pressure, control device and pressure switch of an ordinary oil burner heating system; Fig. 2 is a side elevation of the pump with its cover removed to show its interior construction and F ig, 3 is a vertical cross section taken on the line 33 of Fig. 2.

Referring to said drawing and first to Fig. 1, the reference character 5 designates a variable delivery oil pump embodying a. simple form of the present invention, 6 designates-a diaphragm steam pressure controlling device,

of the ordinary kind employed in oil burner steam heating plants for operating the pressure switch and said pressure switch may be wired in series with a thermostat located in one of the rooms heated by the system. As is well understood the oil pump is driven by an electric motor (not shown) which is controlled from the pressure switch 7 and suitable ignition means, such as a spark plug is connected .with the electric circuit and placed adjacent the burner whereby the oil may be ignited whenever the switch is closed and the motor started. The motor operates the oil pump, which delivers the oil to an atomizer or to the oil burner in the usual manner..

Referring now to Figs. 2 and 3, the oil pumping mechanism illustrated is of common and well known construction. It comprises a pump casing 10, having a chamber 11, preferably cylindrical in form and having an arcuate oil inlet port 12 and an arcuate oil outlet port 13. The oil supply pipe 14 connects with the inlet port 12 through an oil passage 15 and the oildelivery pipe 16 connects with the outlet port 13 through a passage 17. A rotatable disc like cylinder 18 covers the inlet and outlet ports 12, 13, and

der 18 and is held in contact with the inner face of an annular member oreccentric ring 22, by the plunger spring, which ring is eccentrically disposed with respect to the axis o1 the cylinder 18 whereby as said cylinder is rotated, the plunger is reciprocated in the bore 19 as the plunger travels about the ring.

The cylinder 18 is usually rotated by an elec-' tric motor and it is here shown as formed with a stud shaft 23 journaled in the pump casing and connected with the motor shaft24l. lhe cylinder 18 is usually held in place over the inlet and outlet ports 12, 13, by a spring 25 confined between the cylinder and the head or cover 26 of the pump casing. The eccentric ring 22 is adjustable or movable across the axis of the cylinder 18 whereby the amount of the eccentricity between the ec centric ring and cylinder may be varied and it is here shown as pressed in one direction by two coiled compression springs 27 secured in the pump casing and bearing against one side of the eccentric ring, and a stem 28 slidably mounted in the pump casing opposite the compression springs 27 and bearing against the side of the eccentric ring opposite said springs. By moving the stem 28 toward the axis of the cylinder 18 the degree of eccentricity between the eccentric ring and cylinder is increased as is indicated bythe dotted lines in Fig. 2 and by moving said stem away fromthe axis of thetcylinder 18 the degree of eccentricity is lessened since the coil com pression springs act to yieldingly hold the eccentric ring against the end of the stem 28. the exact form of pum described is not material to this invention roadly considered but serves very well for the purpose of illustrating the invention.

The stem 28 extends through a packing box 2 29, which is threadedly secured in the wall of the casing 10 and said stem is engaged by a lever 30, here shown as pivotally mounted upon a bracket 31 secured to the pump casing. It is quite evident that downward movement of said lever 30 causes the stem 28 to be moved toward the axis of the cylinder 18 thereby moving the eccentric ring downward and decreasing the degree of eccentricity between the cylinder and eccentric ring and permitting a greater stroke of the plunger. Movement of said lever in the opposite direction causes a reversal of such action. The

lever may be provided with a weight 32 ad-' morass other connecting medium. The lever 30 is also connected to the switch lever 9 of the pressure switch 7 by a link or other connection 34.

Upon the stem 28 is an adjustment nut 35, which is arranged to engage with the underside of a shoulder 36 formed on the bracket 31' and thereby limit the minimum stroke of the oil plunger. [a lock nut 37 may be employed behind the adjustment nut 35 for locking the same in place upon the stem. Another adjust-ment nut 38 is provided upon the stem 28 above the shoulder 36 and operates by engagement with said shoulder to limit the maximum stroke of the oil plunger. A lock nut 39 may be provided above the adjustment nut 38 for locking said nut in place. Movement of the stem is therefore limited irrespective ot the movement of the diaphragm arm. Moreover the maximum and minimum strokes of the oil plunger may be regulated by adjusting the nuts 35, 38.

In the operation of the pump, the adjustment nuts 35, 38 are set to obtain the maximum and minimum quantities of oil to be delivered by the pump, as may be found desirable, depending upon the temperature of the weather, efiiciency of the boiler and so forth.

When the boiler is cold, or no pressure present therein, the lever 8 of the diaphragm pressure device 6 is down, and consequently the pressure switch is closed, and the lever 30 ot' the pump 5 is down as far as the adjustment nut 38 will permit it to fall and the pump is therefore in adjusted condition for pumping a. predetermined maximum amount of oil. The oil burner system having been set into operation, the oil pump delivers a maximum amount of oil to the burner until sufficient pressure is created in the boiler to affect the diaphragm pressure device 6. As

the lever 8 of the diaphragm pressure device slowly swings upward, the actuating lever 30 for the stroke varying mechanism of the pump plunger is slowly swung upward thereby permitting the plunger actuating eccentric ring to be moved upward, thereby decreasing the degree of eccentricity between the eccentric ring and cylinder 18, in which the plunger is contained and consequently shortening the stroke of the plunger, thereby decreasing the quantity of oil delivered by the pump to the burner. Obviously the boiler pressure is not permitted to rise suddenly to a maximum on account ofthis control of the supply of oil, and when it does reach its maximum the supply has been cut down to a minimum. If the pressure increases above the predetermined maximum limit the diaphragm pressure device lever 8 continues to swing upward, but this does not affect the pump, since the adjustment nut 35.has encountered the stop shoulder 36 and arrested the upward movement of the stem 28. Such continued upward movement of the lever 8,

. stat is located, has not risen suflicientl and as a result the motor circuit is again c osed,

directly after it has been brokeninfhe pump motor will again be'started, but cause the pump is now controlled to deliver only the minimum quantity of oil, there is no danger of explosion in the furnace in case the ignition means fail to operate.

During operation, if the pressure falls at any time the lever 30 swings down, thereby actuating the stroke regulating mechanism for the plunger and increasing the stroke of the plunger, whereby the supply of oil is increased and greater heat created in the furnace.

It will be seen that the volume of oil delivered is governed by the rise and fall of the boiler pressure, and that the pressure switchis used merely as an auxiliary or safety device. A more even and better regulated heat is therefore obtained without any danger from explosions due to the sudden starting of the pump motor while the fire box is extremely hot.

More or less variation of the exact details of construction is possible without departing. from the spirit of this invention; I desire, therefore, not to limit myself to the exact form of the construction shown and described,

but intend, in the following claims, to point' out all of the invention disclosed herein.

I claim as new, and desire to secure by Letters Patent:

1. In variable delivery oil pumps for oil burners of heating systems, the combination of a continuously operating variable volume pumping mechanism, and steam pressure operated means for controlling said variable volume pumping mechainsm, comprising a steam pressure operated diaphragm device,

and operative connections between said steam pressure operated diaphragm device .and the variable volume pumping mechanism.

2. In variable delivery oil pumpsfor oil burners of, heating systems, the combination of a continuously rotating variable stroke plunger, and means for controlling the stroke of said plunger, comprising a' steam pressure operated diaphragm device, and operative connections between said steam presstroke 0 sure operated diaphragm device and the variable stroke plun er.

3. In variable de ivery oil pumps, a va riable stroke, bodily rotating plunger, an adjustable eccentric ring for actuating said plunger and varying the stroke thereof, and means for adjusting said eccentric ring, including an automatically operated actuating member.

4. In variable delivery oil pumps, a variable stroke, bodily rotating plunger, an adjustable eccentric ring engaging with and acan eccentric ring adtuating said plun er,

limited. amount of justing stem, having a movement, and an automatically operated actuating member for said stem.

5. In variable delivery oil pumps, a variable stroke, bodily rotating plunger, a plunger actuating eccentric ring, said ring being adg'ustable to increase and decrease the the plunger, an eccentric ring adjusting stem, adjustable stop members on said stem and a shoulder between said stop members co-operating therewith to limit the operative movements of said stem, and an automatically operated stem actuating lever.

6. In variable delivery oil pumps, a va riable stroke bodily rotating plunger, a plunger actuating eccentric ring, said ring being adjustable to vary the length of stroke lunger, an eccentric ring adjusting stem, a ever operatively engaging said stem of said and a steam pressure device operatively connected to said lever.

7. In variable delivery oil pumps, a vari-' able stroke, bodily rotating plunger, a plunger actuating eccentric ring, said ring bein adjustable to vary the length of stroke 0 said plunger, an eccentric ring adjusting stem, adjustable means for limiting the length of stroke of said stem, gaging said stem and a steam pressure device operatively connected to said lever.

8. In varlable delivery .oil pumps, a variable stroke, bodily rotating plunger, a plunga lever operatively ener actuating eccentric ring, Said ring being adjustable to vary the length of stroke of said plunger, an eccentric ring adjusting stem, stroke limiting nuts adjustably mounted on said stem and a co-operating stop shoulder co-operating therewith to limit the len th of stroke of said stem, a lever operative y engaging said stem and a steam pressure de vice operatively connected with said lever.

EMIL o. ZISTERER. 

